Question

guided practice
which is a disadvantage resulting from the construction of dams and reservoirs?
a. uncontrolled flooding
b. reduction of water - flow speed
c. alteration of ecosystems
d. stored water for irrigation

Explanation:

• Option A: Dams prevent uncontrolled flooding, so this is an advantage, not a disadvantage.
• Option B: Reduced water-flow speed is a controlled effect, not a negative disadvantage.
• Option C: Dams/reservoirs disrupt natural habitats, alter river ecosystems, and harm species, which is a clear disadvantage.
• Option D: Stored water for irrigation is a key benefit of dams, not a disadvantage.

Answer:

C. alteration of ecosystems